Easton's Bible Dictionary (1897)
A water-course or channel (Job 38:25). The “conduit of the upper pool” (Isa. 7:3) was formed by Hezekiah for the purpose of conveying the waters from the upper pool in the valley of Gihon to the west side of the city of David (2 Kings 18:17; 20:20; 2 Chr. 32:30). In carrying out this work he stopped “the waters of the fountains which were without the city” i.e., “the upper water-course of Gihon”, and conveyed it down from the west
through a canal into the city, so that in case of a siege the inhabitants of the city might have a supply of water, which would thus be withdrawn from the enemy. (See SILOAM.) There are also the remains of a conduit which conducted water from the so-called “Pools of Solomon,” beyond Bethlehem, into the city. Water is still conveyed into the city from the fountains which supplied these pools by a channel which crosses the valley of Hinnom.
Smith's Bible Dictionary (1863)
meaning an aqueduct or trench through which water was carried. Tradition, both oral and as represented by Talmudical writers, ascribes to Solomon the formation of the original aqueduct by which water was brought to Jerusalem.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
CON'DUIT (te'alah in Hebrew). 2 Kgs 18:17; 2 Kgs 20:20; Isa 7:3; Isa 36:2. Used to signify something for conveying water, as a "water-course," Job 38:25, or a "trench." It probably included an aqueduct, such as must have been used to convey the water from the Pool of Solomon to Jerusalem. Pilate built a new aqueduct or repaired that of Solomon, which still remains.